Showing 6 results for Immunization
Volume 10, Issue 3 (8-2024)
Abstract
Background: Assessment of rubella immunity coverage relies on regular updates. This study aimed to determine the age-specific seropositivity rates among a large cohort of pregnant women approximately 12 years after vaccine introduction in Tunisia, where serosurveys are both old and scarce.
Materials & Methods: A prospective cohort study was conducted on pregnant women referring to the Maternity and Neonatology Center of Tunis in 2017. Eligible and consenting participants underwent blood sampling twice with a 15-day interval to detect and measure rubella-specific IgG and IgM antibodies. Demographic and obstetric data were also gathered.
Findings: A total of 800 participants with a mean age of 30.6±5 years (range: 17-48) were enrolled in this study. The overall seropositivity rate was 90.4% (n=723) (95%CI: 88.3-92.4). Also, 77 (9.6%) (95%CI: 7.6-11.7) participants were seronegative, among them 36 cases were in the first trimester of their pregnancy. The WHO minimum rubella immunization threshold of 95% was achieved for the first time in the 12-year-old vaccination program target population (96%) (95%CI: 92-99.8). No significant association was found between seropositivity rates and age, geographic origin, occupation, gestational age at the time of enrollment, parity, and abortion history (p> .05), but a significant association was found with educational levels.
Conclusion: Pregnant women vaccinated at the age of 12 showed a high immunization rate. Next decades would witness the elimination of rubella virus circulation as well as congenital rubella syndrome.
Elahe Afsharipour, Ghobad Azari Takami, Seyed Mohammad Jalil Zorriehzahra, Abbas Ali Motallebi, Shapour Kakoolaki,
Volume 11, Issue 1 (3-2022)
Abstract
In this study, the effectiveness of 4 killed VNN vaccines along with three types of adjuvants was evaluated by both immersion and injection methods. About 540 fish weighing 7-10 g of ozone (Acipenser stellatus Pallas 1771) were considered. Vaccination was performed in two stages one month apart, and one month after the second recurrence, exposure to the acute live virus was performed. During this period, the mortality rate of immersion and injection groups was 12.9% and 19.8%, respectively, compared to 100% mortality in the control group. Blood sampling was performed to assess immune factors (superoxide dismutase, lysozyme) in four stages before the first vaccination in the adaptation period, after the first vaccination, after the second vaccination one month and after exposure to live virus Acute was performed to identify changes before and after exposure to the virus. The results of the present study showed that immunization vaccination in the vaccinated group with the vaccine containing IMS 1312 SEPPIC adjuvant significantly higher levels of superoxide dismutase 1745 IU / MI (p<0.05) and lysozyme 40.6 (p<0.05). Compared to other groups, which proves its better efficacy compared to other vaccines. Therefore, a vaccine killed with 75% IMS 1312 SEPPIC adjuvant can be recommended for vaccination against VNN.
Volume 13, Issue 4 (1-2023)
Abstract
Immunotoxins are an attractive way to treat cancer; in this method, high-cytotoxic protein toxins target cancer cells specifically. An immunotoxin consists of a targeting component (an antibody, cytokine, or other protein that binds to the cell), that is chemically conjugated or fused in DNA level to a cytotoxic cargo (a bacterium, plant or cytotoxic human protein). Immunotoxin, with the help of specific receptors, recognizes the target cell and enters the cell by endocytosis. After entering the cytocell, it kills the target cancer cell with the help of a toxic component. Although various immunotoxins with different structures have been studied and tested in recent decades, only three immunotoxins Denileukin Diftitox, Tagraxofusp and Moxestumomab Pasudotox - have been clinically approved for the treatment of leukemia. In this article, we review important research and two challenges in production and development of immunotoxins that have limited their clinical success. Further, we highlight methods to overcome these obstacles. These challenges include target and non-target cell toxicity and immunization.
Volume 17, Issue 2 (6-2014)
Abstract
Objective: Infectious microorganisms are major sources of illness and death worldwide, and the leading cause of death in neonates. Effective vaccination of this age group is of particular importance. The lack of a response and greater susceptibility to tolerance are two major features that limit the effectiveness of vaccines in neonates. In this study we compare the cellular immune response generated following antigen injections at different times of life in newborn mice to that of adult mice. Methods: Adult and different age neonate mice were vaccinated with vesicular stomatitis virus (VSV). One week after the last injection, cellular immunity was assayed on spleen cells that targeted EL4 infected cells using lactate dehydrogenase cytotoxicity assay. Results: Antigen injection induced a decreased immune response in newborn mice compared with mice that had been immunized with subsequent injections. In the adult group, due to the evolution of the immune system, we observed a stronger immune response. Conclusion: Immunization of newborn mice may induce a reduced response when compared to adult vaccinations. However this can be corrected by the administration of additional booster doses.
Volume 18, Issue 4 (1-2016)
Abstract
Objective: Enterohemorrhagic Escherichia coli (EHEC) which produces shiga-like toxin type 2 (Stx2) is a major cause of bloody diarrhea. This pathogen can lead to hemolytic uremic syndrome (HUS) and renal failure with a high mortality rate. Stx2 is the major virulence factor of EHEC. Neutralization of toxin by specific antibodies is known to be the best way to prevent and cure HUS. In this study, we describe the cloning, expression, purification, and immunization of the Stx2B subunit which is responsible for toxin binding to the target cell surface.
Methods: The Stx2B gene was amplified by PCR and subcloned into a pET28a expression vector and transformed into E. coli BL21-DE3. We evaluated recombinant protein expression and rSTX2B was purified by the Ni-NTA column. The purified rSTX2B was administered subcutaneously to BALB/c mice in three separate doses as an immunogenic candidate. The raising of anti-rSTX2B antibodies in immunized mice sera was evaluated by Elisa assay. The neutralizing immune response was verified by an in vitro assay on HeLa cells and an in vivo assay on mice by challenging them with a lethal dose of Stx2.
Results: The IgG titration verified the induction of a humeral response in immunized mice. The HeLa cell assay indicated that the Stx2 toxin was neutralized by immune mice sera. In the challenge assay, 70% of immunized mice survived.
Conclusion: Recombinant rSTX2B can induce a neutralizing immune response in mice. It can be used as a major component in development of EHEC vaccines.
Volume 21, Issue 2 (7-2018)
Abstract
Aims: Developing an effective vaccine against Human Immunodeficiency Virus (HIV) is necessary. The aim of this study was the immunological evaluation of HIV-1 VLP harboring MPER-V3 in BALB/c mice model.
Materials and Methods: In the present experimental research, presenting 40 female mice, which were between 6 and 8 weeks old, were used for immunization with VLP MPER-V3. The mice were divided into 8 groups and in each group, 5 mice were considered. Injections were performed three times at three weeks intervals and subcutaneously in a volume of 100μl per mouse. Two weeks after last injection, mouse blood samples were collected by retro-orbital bleeding and immune responses were evaluated in serum for levels of total IgG and splenocytes for cytokine assay, using ELISA method. The data analysis was performed, using Mann-Whitney test and one-way analysis of variance.
Findings: The level of total antibody production was very high in all groups that had VLP alone or with adjuvant immunity, having a significant difference with the control group (p<0.05). IgG1 was the predominant isotype (Th2-biased response) in groups that had VLP injections alone or with adjuvant.
Conclusion: VLPs can stimulate the humoral immune system in mice immunized with these particles alone or formulated with adjuvant. Also, the level of production of IL-5 in the presence of the vaccine candidate as VLP increased significantly.
